1. Field of the Invention
The present invention relates to an alignment device for guiding a hand manipulated power cutting tool and aligning the cutting edge of the power tool along a line of cut on a workpiece.
2. Description of the Prior Art
In the use of hand manipulated power tools for cutting planar workpieces such as boards, wall board and lumber, it has generally been necessary to provide a means for physically guiding the power tool to obtain a straight, clean cut along a predetermined, desired line of cut on the workpiece. Generally this has required marking the desired line of cut on the workpiece. After the workpiece is placed on a bench or table, a board or other straight edge which services as a guide means for the power tool is placed along a second predetermined line parallel to the desired line of cut and set back a distance equal to the distance between the cutting edge of the power tool and the guiding edge of the guide shoe on the power tool. When it is necessary to make a long cut on a large workpiece, multiple extensions of the line for the cutting edge are drawn on the workpiece and additional boards or other guiding means must be attached to the workbench or workpiece.
Heretofore various mechanisms have been proposed for guiding power driven cutting tools. Examples of such mechanisms are disclosed in the following U.S. Pat. Nos.
______________________________________ U.S. Pat. No. PATENTEE ______________________________________ 2,589,554 Killian 2,396,524 Bridwell 2,714,903 Miller 2,802,493 Horneland 2,860,014 Short 3,964,360 Schwartz 3,991,643 Girardin 4,031,794 Leihgeber 4,041,824 Wynn ______________________________________
The Schwartz U.S. Pat. No. 3,964,360 discloses a sheet material cutting apparatus which does not require the guide thereof to be clamped to a workbench or table. However, the guide and non-powered cutting tool travel in a slot located in the center of the apparatus and would not be adaptable to guide a hand held power tool. Further, this apparatus is utilized for cutting thin material and is designed for a knife edge rather than a power tool.
In the Wynn U.S. Pat. No. 4,041,824 there is disclosed a location apparatus which can be affixed to a workpiece without the necessity of having a workbench for providing a guide for a power tool. However, this apparatus is designed to hold the workpiece in a variety of positions and does not provide for a simple "lay on" of an alignment device on the workpiece as obtained with the alignment device of the present invention.
As will be described in greater detail hereinafter, the alignment device of the present invention differs from the devices disclosed in the patents identified above by providing for a simple "lay on" device which can be clamped directly to the workpiece thus avoiding the necessity for having a workbench or table, while simultaneously providing an alignment edge along the desired line of cut on the workpiece avoiding the necessity of making marks on the workpiece and for guiding the shoe of a power tool in parallel relationship to the alignment edge. Further, the alignment device of the present invention can be readily adjusted to fit a variety of hand manipulated powered cutting tools having different distances between a guide edge of the guide shoe thereof and the cutting edge of the power tool. Further, several of the alignment devices can be coupled together to form a single elongate guide surface and elongate alignment edge for the guiding of a hand manipulated power tool on long workpieces.